Limp-In Mode

Limp-in mode is the attempt by PCM to compensate for failure of certain components by substituting information from other sources so that vehicle can still be operated. If PCM senses incorrect data or no data at all from MAP sensor, TP sensor, ECT sensor or battery voltage, system is placed into limp-in mode and Malfunction Indicator Light (MIL) on instrument panel comes on.

If faulty sensor comes back on line, PCM will resume closed loop operation. On some vehicles, MIL will remain on until ignition is shut off and vehicle is restarted. To prevent damage to catalytic converter, vehicle should NOT be driven for extended periods in limp-in mode.